Safety latch assembly

ABSTRACT

A safety latch assembly has a rotatable grip rotatably mounted on a stationary handle and a ring-shaped flange surrounding a substantially cylindrical portion of the stationary handle, an elastically resilient arresting means on the cylindrical portion whose exterior is formed with an arresting face with which a stop face on the inner side of the grip flange engages upon rotation of the grip in the opening direction from the closed position when the arresting means is in the normal position. The grip is arranged so that the arresting means can be actuated through the flange of the grip to disengage the arresting face from the stop face.

CROSS REFERENCE TO RELATED APPLICATION

This United States application stems from PCT International ApplicationNo. PCT/DK84/0015 filed Nov. 27, 1984.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a safety door latch assembly of the typecontaining a rotatable grip with a ring-shaped flange surrounding asubstantially cylindrical portion of a stationary handle element havingan elastically resilient arresting means whose exterior is formed withan arresting face which a stop face on the inner side of the grip flangewill engage upon rotation of the grip in the opening direction from theclosed position when the arresting means is in an unaffected position,the grip being so arranged that the arresting means can be actuatedthrough the flange of the grip to disengage the arresting face from thestop face .

2. Description of the Prior Art

In the Danish Patent Application No. 2961/83 such a safety closure isshown and described for medicine bottles and similar containerscontaining substances which may be dangerous to children.

BRIEF SUMMARY OF THE INVENTION

The invention is based on the finding that it may be desirable toprotect not only individual medicine containers, but also cabinetcompartments in which such containers and other objects dangerous tochildren, such as razor blades and pointed scissors, are kept, and thepresent safety latch assembly can be used for this purpose withoutdifficulty.

Accordingly, the safety latch assembly of the invention is characterizedin that it is mounted on a cabinet with a door so as to prevent andallow, respectively, opening of the door in two different rotarypositions of the grip.

This use permits the elastically resilient arresting means to beprovided in a particularly expedient manner.

Another expedient detail is an embodiment of the latch assembly in whichthe arresting means, instead of being actuated by a thin-walled portionof the ring-shaped flange of the grip, is actuated by a specialactuation means. The actuation means may be directly accessible from theoutside.

In another embodiment of the locking mechanism itself, the latchassembly may be reclosed after having been opened, without the griphaving to be rotated back to its starting position.

Further embodiments of the turn latch enable the door to be clampedsomewhat upon rotation of the grip, and provide for snap-closing of thelatch assembly irrespective of the rotary position of the grip.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained more fully below with reference to theaccompanying drawing, wherein

FIG. 1 is a cross-sectional view through a portion of a cabinet wall anda hinged cabinet door fitted with an embodiment of the safety latchassembly of the invention;

FIG. 2 is a perspective view of the grip of the latch assembly;

FIG. 3 is a cross-sectional view taken along the line III--III in FIG.1;

FIG. 4 is a perspective view of the grip for another embodiment of thelatch assembly of the invention; and

FIG. 5 is an enlarged cross-sectional view of parts of the grip andstationary element of this closure with the arresting means of the gripin blocking engagement with the stop face of the stationary element.

DETAILED DESCRIPTION

In FIG. 1, the numeral 10 designates a side wall in a cabinet for thestorage of medicine or other objects which may be dangerous to children,and the numeral 11 designates a door which is hinged at one side edge(not shown) and whose shown side edge mounts a safety latch assembly ofthe invention. This latch assembly has a stationary closing elementgenerally designated 12 and a rotary closing element generallydesignated 13.

The stationary closing element 12 is formed by a body of revolution,which preferably consists of a suitable plastics material which isrelatively rigid and hard while possessing some elasticity. The closingelement 12 has a head disposed on the outer side of the door and formedwith a substantially frusto-conical inner portion 14 and a substantiallycylindrical outer portion 15. The element 12 has moreover a stem 16extending through a hole in the door. This stem, which is threaded,mounts a nut 17, by means of which the stationary element 12 is fixed tothe door 11. At the foot of the stem 16 the end face of thesubstantially frusto-conical portion 14 has a ring-shaped groove inwhich a sealing ring 18 may be disposed.

The two portions 14 and 15 of the head of the stationary element 12 arepartly spaced from each other by an annular narrow groove 19, which isdisposed in a radial plane and extends from the periphery a distanceinto the head. The substantially cylindrical portion 15 is formed withtwo diametrically opposite, arc-shaped axially through-going slots 20 inthe region defined by the groove 19; these slots 20 each extend along aportion of the peripheral area of part 15 and are outwardly defined by arelatively thin strip of material 21, which is formed at the middle ofits exterior with an arresting face 22 disposed in an axial plane andwhich forms an elastically resilient arresting means.

The stationary element 12 has moreover an axially extendingthrough-going central hole 23 which rotatably mounts a shaft 24 formingthe rotary closure element together with a turn latch 25 firmly mountedon said shaft and a substantially disc-shaped grip 26. The outermostportion of the central hole has a greater diameter than the remainingportion so as to provide an annular space 27 around the shaft 24 toreceive a helical spring 28, which surrounds the shaft 24 and whose oneend is attached thereto, while the other end portion 29 is bentoutwardly and so engages the wall defining the space 27 as to form apawl which allows rotation of the rotary element 13 in one direction,but essentially prevents rotation in the opposite direction.

The grip 26 has a ring-shaped, cylindrical edge flange 30 enclosing thesubstantially cylindrical portion 15 of the stationary element 12. Theedge flange 30 is formed with a recess 31 on two diametrically oppositepoints on the inner side, said recess 31 extending along a portion ofthe periphery and a distance in an axial direction from the free edge ofthe flange. The thin wall portion 32 defined by each recess 31 isseparated from the rest of the flange by two cuts 33, one of whichextends axially and, the other of which extends circumferentially sothat this wall portion forms a resilient tongue. The end face 34 of therecess 31 disposed at the free end of this tongue forms a stop face forcooperation with the arresting faces 22 on the arresting means 21 of thestationary closure element.

The free end portion 35 of the shaft 24 has a hexagonal cross-section,and the turn latch 25 is secured to this end portion, as mentionedpreviously, e.g. as shown by means of a screw 36 screwed into a threadedhole in the end of the shaft 24. The turn latch 25 has a hub portion 37and two helicoidally shaped latch elements 38 staggered from each other,each said latch element extending through approximately 180° of theperiphery of the hub portion. The turn latch 25 cooperates with alocking hook or catch 39 on a spring 40 which is attached to the innerside of the cabinet side wall 10. The locking hook 39 is defined at oneside by an inclined cam edge 41.

In FIG. 1 the door 11 is shown in its closed position and retained inthis position as one latch element 38 is disposed behind and arrestedagainst movement in the opening direction of the door by the lockinghook 39. Canceling of this arrest requires turning of the latch 25 untilone end edge of the latch element 38 has passed the locking hook 39.However, upon rotation of the grip 26, the stop faces 34 of the gripwill be engaged by the arresting faces 22 on the arresting means 21 ofthe stationary element as shown in FIG. 3, thus preventing furtherrotation. The locking engagement thus established between the stop faces34 and the arresting faces 22 can now be released by an externalpressure in the inward direction of the elastic tongues 32 of the gripwhich thus press the arresting faces 22 of the arresting means 21 out ofcontact with the stop faces 34. The grip 26 can then be rotated freelyuntil the active latch element of the turn latch 25 clears the lockinghook 39 and thus allows opening of the door 11. Closing of the door canbe effected by pressure alone as the locking hook 39 will then bepressed aside by one latch element 38 owing to the cam effect betweensaid element and the cam edge 41 of the locking hook. When the latchelement has passed the locking hook, the spring 40 snaps it back to theshown locking position.

The rotary latch assembly shown in FIGS. 4 and 5, like the one shown inFIGS. 1-3, has a cylindrical flange 30 with two diameterically oppositerecesses in the inner side. These recesses are here designated 40 andare defined at one end by a substantially axially extending wall 48forming a stop face and at the other end by a curved wall 42 forming ahinge bearing for one end edge of an actuation means formed as a curvedplate 43; the actuation means has on its outer side a rib 44 whichprotrudes through a slot 45 in the thin flange wall portion 46 definedby the recess when the actuation means is positioned in the rotaryclosure part as shown in FIG. 5. In this figure the parts are shown intheir blocking position with the arresting face 22 in engagement withthe stop face 48. It will be seen that the blocking can be released byapplication of pressure on the protruding portion of the ridge 44 of theactuation means, causing said means to pivot about its hinge bearing 42and pressing the arresting face 22 inwardly past the edge of the stopface 48 so that the rotary closure element can then be freely rotated toopen the safety latch assembly.

The details of the safety latch assembly of the invention can be formedin many other ways than those shown in the drawing and described in theforegoing, and the latch assembly may also be used in other connections,e.g. in connection with slide doors.

I claim:
 1. A safety latch assembly for a cabinet door which preventsand allows opening of the door in two different rotational positions ofa rotatable grip on the latch assembly, respectively, comprising:astationary handle element; a substantially cylindrical portion on saidhandle element; an elastic resilient arresting means on said cylindricalportion having an outer surface; an arresting face on said outer surfaceof said arresting means; a rotatable grip rotatably mounted for rotationbetween latching and unlatching positions; an annular flange on saidrotatable grip surrounding said substantially cylindrical portion ofsaid arresting means and having an inner side; a recess in said annularflange having opposite edges; a stop face on said inner side formed byone of said opposite edges of said recess engageable with said arrestingface, said arresting means being displaceable in said recess; adepression on the other of said opposite edges forming a bearingsurface; and a pivotable actuation means engaging said bearing surfacefor pivotable movement with respect to said annular flange andengageable with said arresting means, so that rotation of said grip inthe unlatching direction is prevented by engagement of said stop facewith said arresting face when said arresting means is in a normalposition and actuation of said actuation means releases said arrestingmeans by disengaging said arresting and stop faces to allow rotation ofsaid grip into the unlatching position.
 2. A safety latch assembly asclaimed in claim 1 and further comprising:a thin wall portion on saidannular flange defining an outer extremity of said recess; a hole insaid thin wall portion; and a protruding portion on said actuation meansprotruding through said hole.
 3. A safety latch assembly for a cabinetdoor which prevents and allows opening of the door in two differentrotational positions of a rotatable grip on the latch assembly,respectively, comprising:a stationary handle element; a substantiallycylindrical portion on said handle element; an elastic resilientarresting means on said cylindrical portion having an outer surface; anarresting face on said outer surface of said arresting means; arotatable grip; a shaft on said rotatable grip extending rotatablythrough said stationary element and having an inner end thereon, saidshaft rotatably mounting said grip for rotation between latching andunlatching positions; an annular flange on said rotatable gripsurrounding said substantially cylindrical portion of said arrestingmeans and having an inner side; a recess in said annular flange havingopposite edges; a stop face on said inner side formed by one of saidopposite edges of said recess engageable with said arresting face, saidarresting means being displaceable in said recess; a stationary catchmeans mounted adjacent said inner end of said shaft in the latchingposition; and a turn latch mounted on said inner end of said shaftengageable with said catch means when said rotatable grip is in thelatching position and disengageable from said catch means when saidrotatable grip is in the unlatching position.
 4. A safety latch assemblyas claimed in claim 3 wherein said stationary catch means comprises:anelastically resilient mounting member; a locking hook having a turnlatch engaging surface for engaging with said turn latch in saidlatching position; and a cam face on said locking hook engageable withsaid turn latch during movement of said latch assembly toward said catchmeans so that said locking hook will be cammed away from said turn latchuntil said engaging surface is in position for engaging said turn latchin said latching position.
 5. A safety latch assembly as claimed inclaim 3 wherein said turn latch comprises:a hub portion mounted on saidinner end of said shaft; and a helical rib portion extending from saidhub portion.
 6. A safety latch assembly as claimed in claim 4 whereinsaid turn latch comprises:a hub portion mounted on said inner end ofsaid shaft; and a helical rib portion extending from said hub portion.7. A safety latch assembly as claimed in claim 5 wherein:said helicalrib portion comprises two axially spaced ribs each extending throughappoximately 180° and being staggered with respect to each other.
 8. Asafety latch assembly as claimed in claim 6 wherein:said helical ribportion comprises two axially spaced ribs each extending throughapproximately 180° and being staggered with respect to each other.
 9. Asafety latch assembly comprising:a stationary handle element havingmounting means thereon for mounting said handle stationarily on a firstmember; a substantially cylindrical portion on said handle element; anelastic resilient arresting means on said cylindrical portion having anouter surface; an arresting face on said outer surface of said arrestingmeans; a rotatable grip rotatably mounted on said handle element; anannular flange on said rotatable grip surrounding said substantiallycylindrical portion of said arresting means and having an inner side; arecess in said annular flange having opposite edges; a stop face on saidinner side formed by one of said opposite edges of said recessengageable with said arresting face for preventing rotation of saidrotatable grip in one direction, said arresting means being displaceablein said recess; a stationary catch means for mounting on a secondmember, said first and second members being relatively movable withrespect to each other between latching and unlatching positions; a turnlatch mounted on said rotatable grip to be rotatable therewithreleasably engageable with said stationary catch means by rotation ofsaid rotatable grip when said first and second members are in saidlatching position; and actuating means on said annular flange engageablewith said arresting means for disengaging said arresting and stop facesto allow rotation of said rotatable grip upon actuation of saidactuating means.
 10. A safety latch assembly as claimed in claim 9wherein:said arresting means is formed by an arc-shaped slot extendingalong a portion of the peripheral area of said substantially cylindricalportion.
 11. A safety latch assembly as claimed in claim 10 wherein:saidsubstantially cylindrical portion is defined in one axial direction byan annular groove in said stationary handle element.